<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8" />
		<title>demo</title>
	</head>
	<body>
		<script type="text/javascript" >
			let data = function(){
				return {
					a:1,
					b:2
				}
			}

			let x = data()
			x.a = 100
			x.b = 200
			console.log(x)


			let y = data()
			console.log(y)


		</script>
	</body>
</html>